I've lost a PAGES document

Pages does not delete files, but it does save a document in its last save location. Your document may be there. That document should also be the topmost item in your File menu > Open Recent menu.

Another method to locate a missing Pages document would be the following from the Spotlight 🔍 menu tool using this syntax to locate any Pages document created after (>) Dec 1:

kind:pages created:>12/01/2024

Pages will only activate autosave when you initially and manually save a document with a name. If you open Pages and start typing and quit Pages without saving that document once, the temporary document and all content is permanently lost.